Presentation on theme: "Journal 10/18 Explain why you should care about the invasive species of flatworm called bipalium? How would an invasion of this worm affect you personally?"— Presentation transcript:
1 Journal 10/18Explain why you should care about the invasive species of flatworm called bipalium? How would an invasion of this worm affect you personally?Get out your “Plethora of Planaria” lab so we can take day 2 observations
2 UNIT 3A- PHYLUM PLATYHELMINTHES Parasitic Flukes & Tapeworms
3 CLASS TREMATODA Common name- flukes Endoparasitic- live inside host Wide, flat with oval or elongate bodiesHave 2-3 hostsIntermediate hosts- where asexual part of life cycle occursDefinitive host- final host where sexual part of life cycle occursAlmost all adult flukes are parasites of vertebrates (fish, frogs, turtles, livestock, and humans)Internal anatomy is similar to Turbellarians (planarians).
4 CLASS TREMATODA EX: Liver Flukes Types:Chinese liver fluke- common parasite of humans that live in Asia.Sheep liver fluke- common in sheep or people who raise sheepLives in the liver where it eats tissue & blood.Contracted byEating uncooked contaminated food (sushi)Eating water plants (water cress) infected with larvae
5 CLASS TREMATODA EX: Liver Fluke Signs & Symptoms:Enlarged liverFeeling of fullnessAbdominal discomfortJaundiceFatigueWeaknessNauseaWeight lossDetection: look for eggs in stool or larvae in bloodTreatment: triclabendazole
6 Liver Fluke Life Cycle Eggs passed out w/feces Eggs ingested by a snail- the first intermediate host.Inside the snail, the eggs undergo asexual reproduction & metamorphosisMiracidia- cilia for swimmingSporocysts- asexual reprod.Rediae- worm like stageCercariae- has tail for swimmingFree swimming cercariae burrow out of skin of snail and search out fish or plant- the second intermediate host.Cercariae encyst in fish/plant and are called metacercariae which is then ingested by a human or other vertebrate.Metacercariae excyst in the intestine and migrate to the liver where they live, feed & reproduce sexually.
7 CLASS TREMATODA EX: Blood Flukes Common in Africa, Asia, S. AmericaCause disease known as Schistosomiasis (A.K.A. bilharzia)Symptoms:Fever & chillslymph node enlargementliver and spleen enlargementfrequent urination, blood in urine and in stoolInvasion in skin may cause rash (swimmer’s itch)
9 CLASS CESTODA Common name: tapeworms Endoparasitic: live inside host Long, flat ribbon-like bodiesWhite w/shades of yellow or graySize: 1mm to 15 m in length (up to 60 ft!)
10 CLASS CESTODA 6. Body Structure Scolex- head-like structure; hooks & suckers for attachment (not feeding)Neck- contains immature proglottids- series of repeating units of reproductive organs.Strobila- rest of body; contains proglottids that are mature and gravid- full of eggs.
12 CLASS CESTODA 7. Digestion a. No mouth or digestive tract. b. Absorb nutrients directly across their body wall.
13 CLASS CESTODA Signs/Symptoms: Nausea & WeaknessLoss of appetiteWeight loss & diarrheaInadequate absorption of nutrients in foodCan lead to Cysticercosis disease in humans where larvae encyst in your muscle.These cysts can end up in brain and cause death.Detection: MRI or Xrays can detect cysts in muscle.Treatment: Depends on infection & location of cysts. Albendazole and anti-inflammatory drugs help but surgical removal may be necessary.
14 California had the highest percentage of fatal cysticercosis from 1990-2002! Frequency and percentage of fatal cysticercosis cases by state, United States, 1990–2002. Shaded areas indicate states with deaths from cysticercosis.California – 57.3% deaths due to this disease.Lots of patients were foreign-born or from Mexico.Mortality rate higher in Latinos and men.
15 Life Cycle of a Tapeworm Eggs or gravid proglottids are passed with feces into environment.Cows, pigs, fish ingest eggs/gravid proglottids from vegetation in environment.Oncospheres (larva) hatch in intestine, burrow thru intestinal wall, and enter circulatory system where they end up in muscle where they become a bladderworm inside a cyst.Humans are infected by ingesting uncooked infected meat.Bladderworm will hatch in stomach and migrate to intestine where they attach to intestinal wall with hooks and suckers and begin absorbing nutrients.Adults sexually reproduce in final vertebrate host (human)
16 Life Cycle of Tapeworm in Dog Tapeworm inside fleasDog chews when flea bites and ingests fleasDog may also eat feces infected with tapeworm eggs/proglottidsTapeworm Lifecycle Movie - YouTube
17 Environmental/Economic Significance of Parasitic Flatworms Cause disease in vertebrates in many countriesMust study the worms to figure out how to treat infected people.